Aircraft: RV-4
Phase of flight: Cruise
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue

In Day VFR CAVU cruise flight at 11;500 MSL over mountainous terrain; I inadvertently and unexpectedly ran the right fuel tank dry causing the engine to quit. I switched to the left tank but the engine refused to restart despite the windmilling propeller. Fuel pressure remained at zero even though I tried the electric fuel boost pump; leaning and enriching the mixture. I even tried going back to the right fuel tank but nothing changed so I reverted to the left tank again since I was certain that it had to have fuel since I had visually verified the fuel quantity in each tank during my pre-flight inspection. The engine is fuel injected hence no carb heat was available nor needed (but I'd have tried anything at that point). I cycled the mag switch off then back on; cycled the throttle and quickly rechecked everything one last time. This was all to no avail so I committed to a forced landing.Luckily; Airport (ZZZ1) was within easy gliding distance and I highlighted it on Foreflight on my iPhone (the only long range nav on board) and pointed toward the field. It turns out that I misidentified the field visually and wound up landing at ZZZ despite making all my radio calls on ZZZ1 UNICOM frequency.ZZZ UNICOM traffic informed me that there is only one runway at Cable and since I was calling for right traffic to the right runway I must be at a different airport. By the time I realized my error there was no time or attention to spare trying to find the Tower frequency for ZZZ. I hit my 'high key' on right downwind for Runway 26R and proceeded to a 'low key' abeam the numbers. Landing went well and I touched down just as the prop stopped windmilling about 40% down the runway. I coasted clear of 26R. My co-pilot and I had to push the airplane the last few feet to clear the runway.I initiated a phone call to ZZZ Tower and explained my situation. I felt very embarrassed for my confusion as to location and apologized for barging in unannounced. Tower was extremely pleasant and reassuring. They collected my information. At the time; I suspected a blocked fuel vent on the left side but it tested fine when I blew into it from both the vent tube and by blowing into the fuel tank through the fuel cap opening...it flowed air just fine. Refilling the tanks took quite a bit more fuel than should have been consumed in the 70 minute flight.After fueling both tanks to capacity; the engine started and ran normally on either tank. Fuel pressure indicated normal with either the engine driven pump or the electric boost pump on either tank. An extensive run up verified that normal fuel delivery was occurring. It was decided that we must have experienced a vapor lock; so after much discussion with my friend and experienced and co-pilot for the day we decided to test fly the airplane. Takeoff and climb out were normal so we continued on our way.During the otherwise normal flight from ZZZ to our original destination we noticed a slight mist above and aft of each fuel cap but fuel flow; pressure and level indications remained normal so we continued the flight.Upon further examination at [our destination]; the fuel caps were found to be misadjusted and allowing fuel to siphon out into the slipstream. No characteristic blue staining was visible due to the fact that the wing is painted in metallic light blue. The fuel caps were tightened so as to provide more clamping force on the sealing O-Ring and the return flight from ZZZ2 to ZZZ3 went smoothly with no further difficulties.If the airplane wing were painted white or had a white round-el paint around the fuel cap; I might have seen evidence of the fuel loss in the form of blue staining at the fuel caps.If I had more time in that serial number; I might have trusted the gauges even though they were indicating less fuel than I thought should be present. Basically; I ignored what the gauges were telling me and should have stopped sooner to investigate what appeared to be disappearing fuel as indicated on the fuel gauge.I'm very accustomed to using Foreflight on my iPad but only had my iPhone for the flight in question. I feel screen size played a part in my airport ID error. Also; fumbling with the smaller iPhone; which I dropped several times during the emergency; didn't help. An iPad on a mount would be much safer and will be used in the future.I could have exercised better crew resource management and used my co-pilot in the back seat to handle communications; especially once I realized my airport error on downwind. He could have easily found the correct frequency but I'm not sure I could have spared the time to go 'head down' in the cockpit to select the correct freq. But I could have at least tried if I had thought of it. I'll try to exercise better CRM (Crew Resource Management) going forward.All in all; a very lucky outcome. No injuries; and no damage to anything but my pride. RV-4 pilot reported having to land due to a lack of fuel problem.